川东北龙会—铁山地区飞仙关组鲕滩储层地震地质特征及油气地质意义

Seismic geological characteristics and petroleum geology significance of Feixianguan Formation oolitic beach reservoir in Longhui-Tieshan area,northeastern Sichuan Basin

川东北龙会—铁山地区飞仙关组鲕滩储层广泛发育,钻井测试成果显著,展现出良好的勘探前景。但也存在储层发育层段地震响应特征多变,飞仙关组内部各期次古地貌演化规律不明确,储层横向发育规律不清等问题。在地震地质分析基础上,深入挖掘飞仙关组古地貌演化模式,挖掘储层横向发育规律,从而有效预测鲕滩储层纵横向展布特征。研究表明,飞仙关组鲕滩储层受海退背景的影响而呈现进积趋势,主要发育在每期次台缘带附近。储层纵向上主要发育在Sq3段和Sq2段,横向上发育在龙会场构造、铁山南构造主体和两翼高部位以及蒲包山构造西翼下倾方向,同时研究区走滑断层对油气藏建设具有积极作用,但需要注意后期地质活动对气藏的破坏作用。结果显示研究取得的认识与实际数据吻合度高,对进一步拓展四川盆地礁滩气藏勘探具有积极作用。

The Feixianguan Formation oolitic beach reservoir in Longhui-Tieshan area of northeastern Sichuan Basin is widely developed,and the drilling test results are remarkable,showing good exploration prospects.However,there are also problems,for example,the seismic response characteristics of the reservoir development interval are changeable,the evolution law of the sub-paleogeomorphology in each stage of the Feixianguan Formation is not clear,and the horizontal development law of the reservoir is not clear.Based on seismic geological analysis,this paper deeply excavates the paleogeomorphological evolution mode of the Feixianguan Formation and excavates the horizontal development law of the reservoir,so as to effectively predict the longitudinal and horizontal spread characteristics of the oolitic beach reservoir.The results show that the reservoir of Feixianguan Formation shows an accumulation trend due to the influence of the background of sea retreat,and mainly develops near the marginal zone of each period.The reservoir is mainly developed in the Sq3 interval and Sq2 interval longitudinally,and horizontally in the main body and the high parts of the two wings of the south structure of Tieshan in the Longhuichang structure and the downward dip direction of the west wing of the Pubaoshan structure,and the strike-slip fault in the study area has a positive effect on the construction of oil and gas reservoirs,but it is necessary to pay attention to the destructive effect of later geological activities on the gas reservoir.The results show that the understanding in this paper is in high agreement with the actual data,which has a positive effect on the further exploration of reef beach gas reservoirs in the Sichuan Basin.